How to make Facebook's app new menu on Android? [duplicate]

Question

Possible Duplicate:
Android facebook style slide

Recently Facebook released a new version of its Android application that features an improved navigation. One main new feature is the new menu (that already existed on the iOS version):

By clicking on the home button of the Action Bar, this menu slides from left to right, hiding the main activity that is no longer accessible.

How do you think this menu has been made? Do you think they have just played with the SlidingDrawer or is it something else like a ViewPager?

Thanks!

EDIT

There is no way that it could be one of the two (ViewPager or SlidingDrawer). It's not the menu that slides in, it's the main screen that moves away leaving only a tiny part of it on the screen. It's like if the menu was already behind that main screen and that it just got uncovered. And second thing, we can actually still interact with that main screen (otherwise I would have assumed that they took a screenshot in order to cut a tiny part of it to compose that view).

Answer 1

Almost everything except the photo taking parts is inside a WebView in the new FB app. I could not find any native Android UI controls in the stream or the lists.

Making the same effect using Javascript/HTML/CSS should be quite easy I feel.

Decompiling the apk would give a better idea.